The invention relates to a method for loading a user interface in a television environment, in particular in a digital television system. The invention also concerns a device implementing said method, and an associated smart card. The invention may be used for example in conjunction with decoders in a conditional access television system.
It is known to use microprocessor cards (xe2x80x9csmart cardsxe2x80x9d) in Pay-TV systems. Such cards contain various data, some of which may be accessed and eventually modified by the user. For example, a card may store the access rights to a list of programs. In some systems, this information is transmitted with the video data by the broadcaster, either in specific data packets in digital transmission systems, or modulated on the analog video signal""s vertical blanking interval (VBI) in analog transmission systems. Once received, the data is stored in the card. A user may wish to consult this information, although he may not be able to modify it directly. Other examples of information stored on the card are parental access codes or personal passwords. Such information may be modified by users having the corresponding authorizations.
Television decoders such as digital television decoders sold under the RCA brand for digital satellite reception in the United States are equipped with sophisticated user interfaces. User interfaces of this kind generally include a program guide and decoder feature programming tools, and make use of the graphical capabilities of the decoder to enhance user friendliness. The hierarchical structure of the user interface is presented to the user under the form of a succession of menus, or under the form of a representation of a familiar environment such as a living room or a shopping mall.
The U. S. Pat. 5,367,571 concerns a subscriber terminal with a plug-in expansion card, from which code is downloaded.
The PCT Patent application WO 94/14284 concerns a reprogrammable terminal in a television program delivery system, in which menu templates are created and transmitted to the terminal for storage.
The presentation of specific information to the user and/or the modification of this information by this user require that a part of the user interface be adapted to this information. With the evolution of services offered to the user, the nature of such information changes. The user interface may not always be adapted to process such new types of information. This is particularly true for information stored in a smart card, since such cards are by nature destined to be replaceable. New card versions may carry data concerning formerly unavailable services.
The invention concerns a method for loading a user interface in a television system comprising a decoder and a removable smart card cooperating with said decoder, said decoder comprising a main user interface, said method being characterised in that it comprises the steps of
loading and storing by the decoder of the totality of a user interface module stored on said smart card, said user interface module comprising data structures making reference to information destined to a user, said information being stored on said smart card,
establishing by said decoder a relation between said main user interface and said stored user interface module in order to enable access by a user to said user interface module,
subsequently exchanging between said decoder and said smart card parts of said information upon commands issued by said user through said user interface module.
By storing parameters and data on a smart card, along with a user interface module to manage these parameters and data, and by establishing a relation between the user interface of a decoder and the user interface module stored on the card, a flexible solution is provided to allow evolution of a user interface.
The invention moreover permits the adaptation of the user interface module to each user, according to the data and parameters stored on a specific user""s card.
The loading and storing of the user interface module is performed once and for all. No further loading of a part of the user interface module is necessary, exchanges with the smart card being limited (as far as the user interface is concerned) to that of parameter values. Access frequency and duration to the card""s memory are consequently reduced during use of the user interface by the user.
According to a variant of the embodiment of the invention, said step of loading and storing is performed upon the first detection by said decoder of the presence of a smart card in said smart card interface.
Loading and storing of said module is thus performed as soon as possible when the decoder and card are functional, to free the decoder""s and smart card""s resources before interaction between the user and the decoder takes place.
According to a variant of the embodiment of the invention, said step of establishing said relation between said main user interface and said user interface module comprises the step of identifying at least one entry point into said user interface module and in displaying to said user in said main user interface an access to said user interface module through said at least one entry point.
According to a variant of said embodiment, said information stored in the smart card comprises user-defined data.
According to a variant of said embodiment, said user interface module is stored under the form of at least one linked list of objects.
According to a variant of said embodiment, said at least one linked list of objects comprises a series of screens, at least one screen in each linked list comprising one of said entry points.
According to a variant of said embodiment, said main user interface comprising a predetermined pointer to said at least one entry point, said step of establishing by said decoder a relation between said main user interface and said user interface module further comprises the step of allowing said user to activate a trigger to access said entry point only when said user interface module has been loaded.
According to a variant of said embodiment, said step of establishing a relation between said main user interface and said user interface module further comprises the steps of:
loading from said smart card at least one object to be linked to an object of said main user interface.
In this particular case, the main user interface does not contain in advance any preprogrammed access means which are displayed to the user. When the user interface module is downloaded, the decoder searches for objects whose function it is to establish the bridge between the main user interface and the user interface module. These objects (a specific xe2x80x9cbuttonxe2x80x9d or menu choice) is displayed to the user.
The invention also concerns a smart card comprising a memory, a microprocessor and input/output means characterised in that it comprises data destined to a user, a user interface module to present said information to said user and data identifying bridges between said user interface module to a main user interface module of a device into which said smart card is inserted.
The invention also concerns a video receiver comprising a main user interface, a memory, a memory card interface and a device for entering user commands, characterised in that it comprises:
means for downloading the totality of a user interface module stored in a memory card inserted into said memory card interface,
a memory for storing said user interface module,
means for establishing a relation between said main user interface and said user interface module.